U.S. Pat. No. 5,175,038 relates to a highly bulked continuous filament yarns, comprised of filaments having a denier per filament of 10-25 and a trilobal filament cross section of modification ratio 1.4-4.0, including filament nylon yarns that have a yarn bulk level of at least 35, which can be ply-twisted together to high-twist levels and can be used in carpets at high-twist levels.
U.S. Pat. No. 5,155,178 relates to blends of nylon 6,6, nylon 6 or nylon, 6,6/6 copolymer which contain a randomly copolymerized cationic dye modifier, which are formed by melt blending the copolymer with a polyamide to form a block copolymer that is resistant to staining with acid dyes at ambient temperature and pH, but which can be dyed at pH 2-7 and 60-100.degree. C.
U.S. Pat. No. 5,223,196 discloses terpolymers and interpolyamides which are either block or random. The patent involves making pigmented nylon fiber with decreased draw tension.
U.S. Pat. No. 3,962,159 discloses graft copolymers prepared by condensing a polyamideamine substrate with starch and a condensing reagent.
U.S. Pat. No. 3,846,507 discloses a fiber forming polyamide having basic dye receptivity and reduced acid dye receptivity, comprising a melt polymerized compound of the formula: ##STR1##
wherein R is OH, Cl, OCH.sub.3 or OC.sub.2 H.sub.5 and X is Li, Na, K or NH.sub.4 and wherein the ##STR2##
groups are not ortho to each other.